Merge pull request 'grids2' (#11) from grids2 into master

Reviewed-on: #11

src/hz_grids.erl

@@ -38,14 +38,14 @@
 
 -module(hz_grids).
 -vsn("0.7.0").
--export([url/2, parse/1, req/2, req/3]).
+-export([url/2, url/3, url/4, parse/1, req/2, req/3]).
 
 
 -spec url(Instruction, HTTP) -> Result
     when Instruction :: spend | transfer | sign,
          HTTP        :: uri_string:uri_string(),
-         GRIDS       :: uri_string:uri_string(),
+         Result      :: {ok, GRIDS} | uri_string:uri_error(),
-         Result      :: {ok, GRIDS} | uri_string:uri_error().
+         GRIDS       :: uri_string:uri_string().
 %% @doc
 %% Takes 
 
@@ -66,6 +66,63 @@ url2(Instruction, URL = #{path := Path}) ->
     {ok, uri_string:recompose(GRIDS)}.
 
 
+-spec url(Instruction, Recipient, Amount) -> GRIDS
+    when Instruction :: {spend, Network} | {transfer, Node},
+         Network     :: string(),
+         Node        :: {inet:ip_address() | inet:hostname(), inet:port_number()}
+                      | uri_string:uri_string(),
+         Recipient   :: string(),
+         Amount      :: non_neg_integer(),
+         GRIDS       :: uri_string:uri_string().
+%% @doc
+%% Forms a GRIDS URL for spends or transfers.
+%% @equiv uri(Instruction, Recipient, Amount, "").
+
+url(Instruction, Recipient, Amount) ->
+    url(Instruction, Recipient, Amount, "").
+
+
+-spec url(Instruction, Recipient, Amount, Payload) -> GRIDS
+    when Instruction :: {spend, Network} | {transfer, Node},
+         Network     :: string(),
+         Node        :: {inet:ip_address() | inet:hostname(), inet:port_number()}
+                      | uri_string:uri_string(), % "http://..." | "https://..."
+         Recipient   :: string(),
+         Amount      :: non_neg_integer() | none,
+         Payload     :: binary(),
+         GRIDS       :: uri_string:uri_string().
+%% @doc
+%% Forms a GRIDS URL for spends or transfers.
+
+url({spend, Network}, Recipient, Amount, Payload) ->
+    Elements = ["grids://", Network, "/1/s/", Recipient, qwargs(Amount, Payload)],
+    unicode:characters_to_list(Elements);
+url({transfer, Node}, Recipient, Amount, Payload) ->
+    Prefix =
+        case Node of
+            {H, P}                   -> ["grid://", h_to_s(H), ":", integer_to_list(P)];
+            "https://" ++ H          -> ["grids://", H];
+            "http://"  ++ H          -> ["grid://",  H];
+            <<"https://", H/binary>> -> ["grids://", H];
+            <<"http://",  H/binary>> -> ["grid://",  H]
+        end,
+    unicode:characters_to_list([Prefix, "/1/t/", Recipient, qwargs(Amount, Payload)]).
+
+h_to_s(Host) when is_list(Host)   -> Host;
+h_to_s(Host) when is_binary(Host) -> Host;
+h_to_s(Host) when is_tuple(Host)  -> inet:ntoa(Host);
+h_to_s(Host) when is_atom(Host)   -> atom_to_list(Host).
+
+qwargs(none, "") ->
+    [];
+qwargs(Amount, "") ->
+    ["?a=", integer_to_list(Amount)];
+qwargs(none, Payload) ->
+    [$? | uri_string:compose_query([{"p", Payload}])];
+qwargs(Amount, Payload) ->
+    [$? | uri_string:compose_query([{"a", integer_to_list(Amount)}, {"p", Payload}])].
+
+
 -spec parse(GRIDS) -> Result
     when GRIDS       :: string(),
          Result      :: {ok, Instruction} | uri_string:error(),